Bolsters are commonly used in the construction industry for the support of post-tension cables, rebars, or mesh above a surface. Typically, when such materials are used, they must be supported above the surface when the concrete is poured. These bolsters are used with poured decks. In normal use, the bolster is positioned on the deck and includes a beam which extends across a plurality of leg members. This beam is formed so as to contact and support the rebar while the base of the bolster rests on the deck or on a grade. When the concrete is poured, the bolster will support the rebar a proper distance above the bottom surface.
In normal use, such bolsters are preformed so that they can be installed quickly and easily upon the deck. Conventionally, the preformed bolster will have a plurality of leg members and a steel rod welded to a top surface of each of the leg members. The rod will serve as a receiving area for the rebar. Conventionally, these bolsters are formed in preset lengths. If it is necessary to extend the bolster across a long surface of the deck, then the ends of the beams of adjacent bolsters will be wired together such that the bolsters are in an end-to-end relationship.
The most common bolster that is employed is a metal bolster manufactured by Meadow Steel Products of Tampa, Fla. This bolster has a plurality of inverted U-shaped leg members having outwardly extending foot portions. A rigid tubular rod having a slight waveform pattern formed thereon is welded to the middle of the inverted U-shaped leg members. Each of the leg members is generally arranged in parallel relationship to each other. The feet of each of the leg members will rest on the deck while the rebar is supported. After the concrete has solidified, and the deck is removed, the bottom surfaces of the feet will be exposed. As such, it is necessary to coat the feet with an anti-rust material. Alternatively, stainless steel material can be employed for the leg members and their associated feet.
Corrosion and cost are major problems affecting the bolster of Meadow Steel Products. In order to form such a bolster, a great deal of manufacturing must take place, including metal forming, bending, dipping, and welding. These activities, along with the cost of the material used to form the bolster, make the cost of the bolster relatively expensive. If the bolster is not coated or made of a stainless steel material, then corrosion can adversely affect the product. This corrosion can even occur when the metal is coated.
In the past, various attempts have been made to create bolsters of plastic material that can serve the purposes of the bolster of Meadow Steel Products. In general, such efforts have resulted in plastic chairs that are ineffective, cumbersome to use, or unable to properly withstand the forces imparted by the rebar upon the bolster. One such plastic bolster, manufactured by Conac, includes a central beam which is integrally formed with a plurality of leg members. Each of the leg members extends downwardly so as to present a flat surface to the underlying deck. No feet are provided which allow the bolster to be stapled to the deck. Additionally, the configuration of this Conac bolster allows for easy deformation. It is very difficult and time consuming to join lengths of the Conac bolster together. The Conac bolster also lacks the suitable wave form pattern for the receipt of the rebar on the top surface of the bolster. This plastic bolster is often broken, collapsed, or tipped over in actual use. The base of such a bolster has only a very small area of contact with the deck. As such, these plastic bolsters lack the strength and ability to withstand the loads imparted to them.
It is an object of the present invention to provide a bolster that is corrosion-proof and relatively inexpensive.
It is another object of the present invention to provide a bolster that can be easily connected in end-to-end relationship.
It is a further object of the present invention to provide a bolster that withstands the forces imparted on it.
It is still another object of the present invention to provide a bolster that facilitates the ability to staple the bolster to the deck.
It is still another object of the present invention to provide a bolster that is easy to manufacture and easy to use.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.